Freshly drawn polyamide filaments are commonly annealed with heat while being maintained at constant length to improve their dimensional stability as taught for example in U.S. Pat. No. 3,311,691. Such processes, generally subject the yarn to a controlled relaxation before cooling. These processes are most commonly employed in the manufacture of high tenacity yarns for industrial uses because of the high draw ratios employed to obtain high strength. Various means of assisting the drawing with heating devices are used to facilitate such processes. Assisting the drawing with heat reduces the drawing tension and improves operability of the process. Heat assisted two-stage drawing also is taught in U.S. Pat. No. 3,311,691.
This invention provides a simple means for supplying heat to assist the second stage of drawing in such known processes, eliminating the need for more expensive heat-draw assisting devices of the prior art.